California is now the fourth and largest U.S. state to file a lawsuit against Navient, the nation's largest student loan servicer.

If you have a student loan, there is a good chance that it may be serviced by Navient. Navient, which spun off from Sallie Mae, has more than 12 million customers and services more than $300 billion of government and private student loans.

Here's what you need to know and the action you can take.

The Navient Lawsuit: What are the accusations?

California Attorney General Xavier Becerra announced that California will sue the student loan giant for unlawful business practices, including allegedly causing student loan borrowers to overpay for student loan repayment and not discharging student loan debt for borrowers with a total and permanent disability.

California now follows the actions of other states such as Illinois, Pennsylvania and Washington that have also sued Navient on similar grounds.

The California suit focuses on federal student loans, which are backed by the federal government. According to the California attorney general's office, about 1.5 million Californians have student loans serviced by Navient. According to Make Lemonade, this represents about 3.5% of the more than 44 million student loan borrowers who collectively owe $1.5 trillion in student loan debt.

This follows action from the Consumer Financial Protection Bureau (CFPB), which also sued Navient in January 2017.

The CFPB alleges that, among other allegations, Navient "systematically and illegally [failed] borrowers at every stage of repayment," including:

created obstacles to repayment by providing bad information;

processed payments incorrectly;

failed to act when borrowers complained;

illegally cheated many struggling borrowers out of their rights to lower payments, which caused them to overpay for their student loans;

deceived private student loan borrowers about requirements to release their co-signer from the loan; and

harmed the credit of disabled borrowers, including severely injured veterans

The CFPB also alleges that Navient improperly directed borrowers into forbearance when these borrowers otherwise might have qualified for income-driven repayment plans, and did not adequately keep borrowers in income-driven plans informed of deadlines to maintain their eligibility under such plans.

Illinois, Pennsylvania and Washington also allege that Navient gave student loans to borrowers who were likely to default.

Navient has denied the allegations publicly and in court filings.

“The allegations are unfounded, and the lawsuit is another attempt to blame a single servicer for the failures of the higher education system and the federal student loan program to deliver desired outcomes,” said Jack Remondi, president and CEO of Navient, in a statement.

What Action Can You Take?

When it comes to your student loans, the ball is in your court:

1. Understand all your student loan options

One role of your student loan servicer is to help you understand your available options with regard to your student loans, including:

When it comes to student loan repayment, it's best to conduct your own independent research, rather than rely on your student loan servicer to give you all the answers. For example, you can change your student loan servicer through student loan refinancing. Although it should not be the primary motivation, it is one factor to consider.

2. Follow the potential policy changes and legal developments

There may be several changes to your student loans in the coming years. This may include changes to student loan repayment and student loan forgiveness, among others.

3. Maintain careful records

Keep an organized record of all your student loan payments, including any correspondence with your student loan servicer. It is best to communicate in writing with your student loan servicer.

4. File a complaint

If you feel you have been wronged by your student loan lender or your student loan servicer, you can make your voice heard by sending a formal complaint to: